With support from FHWA and RITA, researchers are integrating the latest camera technology with traffic control to improve safety at intersections
In 2007, more than 4,600 pedestrians died in traffic crashes in the United States, according to the National Highway Traffic Safety Administration (NHTSA). That same year, crashes injured about 70,000 pedestrians. Zeroing in on intersections, NHTSA reports that 984 pedestrians were killed and 31,000 injured in 2005. Although these figures are lower than in previous years, the statistics underscore the continuing need for safety improvements. For instance, children 14 years old and younger accounted for 20 percent of all pedestrian injuries and 7 percent of all pedestrian fatalities. For NHTSA and the Federal Highway Administration (FHWA), even one fatality or injury is one too many. For many systems and applications—such as connected vehicle research, traffic control, security monitoring, and pedestrian counting and flow analysis—pedestrian monitoring could add value.
Specifically, monitoring can help avoid potential harm to pedestrians when collision avoidance measures or emergency vehicle preemptions are imposed when pedestrians are present. And, pedestrian monitoring can help reduce delays, minimize fuel consumption, and limit vehicle emissions by facilitating traffic control optimization when pedestrians are absent. The tide is turning, SBIR researchers have developed a new stereo vision-based approach for detecting pedestrians at intersections. The technique involves a prototype of a new IR, light-emitting diode (LED) stereo camera that can detect pedestrians both during the day and at night. The researchers also developed advanced pedestrian detection algorithms that enable them to extract generic three-dimensional (3-D) features from a stereo disparity map, leaving the human figures behind.
The technology can discriminate pedestrians from vehicles because automobiles appear basically flat, while human bodies have concave shapes. Extended field trials are now underway. Migma has installed the systems at 5 intersections and 5 mid block locations and has already collected more 10,000 hours of field data. Analysis of the data to date has been very promising with approximately 99.2% of pedestrians successfully detected with only 0.8% missed. Additional work with algorithms and analysis is underway in an attempt to improve these already excellent numbers. Migma is also working with traffic signal control industry partners to improve the installation procedures for these advanced sensors.
And what of the ultimate, long-term value of this research? Says Dan Stewart, manager of the bicycle and pedestrian program at the Maine Department of Transportation, "This initiative has the strong potential to improve pedestrian safety and reduce injuries and deaths, as well as improve traffic flow."